Journal of Medicinal Plants Biotechnology

Abstract Medicinal plants are used in various cosmetic, food, pharmaceutical, and medical industries. Artichoke (Cynara scolymus L.) is a perennial medicinal plant that has antioxidant, anticancer, antiinflammatory, antimicrobial, lipid-lowering, and heart and liver-protecting properties due to its phenolic compounds (such as cynarin and caffeoylquinic), flavonoids, inulin, and volatile organic compounds (e.g., methyl salicylate, camphene, and alpha-terpinene). Tissue culture of medicinal plants is widely used to produce secondary metabolites. This study investigated the callus formation of artichoke from explants (leaflet, crown, and rootlet) in culture medium containing NAA (0, 3, and 6 mg L-1) and 2,4-D (0, 0.5, and 1 mg L-1) hormones. The results showed that callus formation occurred in all cultured explants. According to the results of callus weight and dimensions, the best explant for producing callus was the rootlet, and the leaflet had the weakest callus formation. Considering the largest callus dimensions (average 14.3 cm) in rootlet explants cultured in medium containing 6 mg L-1 NAA, rootlet explants and NAA hormone can be suggested for optimizing artichoke tissue culture and callus formation.

Abstract Introduction and Objective: Medicinal plants, as valuable sources of secondary metabolites, play a vital role in various industries. However, the natural production of these compounds is often limited. This review article aims to systematically examine the role and mechanisms of action of nanoparticles (including metallic, non-metallic, and carbon types) as novel elicitors for enhancing the production of secondary metabolites in medicinal plants.
Method and Theoretical Principles: The foundation of this review is based on the analysis of existing scientific evidence, which indicates that nanoparticles activate plant defense signaling pathways by inducing mild oxidative stress and generating reactive oxygen species. This process, in turn, leads to the modulation of key gene expression and the regulation of enzyme activities involved in the biosynthesis of secondary metabolites.
Results: Nanoparticles boost biosynthesis of phenols (2.3‑fold), flavonoids (80%), alkaloids, and essential oils (230%). For instance, essential oil in yarrow rose by 230% and silymarin in milk thistle by 75%. This review covers the shared and distinct mechanisms of these nano‑elicitors in various plants.
Conclusion: In summary, nanoparticles represent a promising and powerful strategy for the sustainable enhancement of the production of plant metabolites with high commercial value. The future perspective of this field includes optimizing the type, size, and concentration of nanoparticles for specific species, more detailed investigation of signaling pathways at the molecular level, and comprehensive assessment of the safety and regulations associated with the use of this technology in agriculture and industry.

Abstract Cross-kingdom regulation of human genes by plant miRNAs has always been a topic of discussion and attention. Several reports have been published on the presence of dietary plant miRNAs in the human digestive tract, raising great hopes for their discovery as potential therapeutics. Recent studies have demonstrated that plant miRNAs can enter the bloodstream and plasma of mammals through the digestive tract, subsequently reaching tissues and cells. miRNAs are a type of single-stranded non-coding RNAs with a length of approximately 19–24 nucleotides, which are known as potent regulators of gene expression. These small molecules can regulate mRNAs by cleavage or inhibition of translation. Therefore, discovering the targets of miRNAs is of great importance in biological research. However, due to their short length and limited sequence complementarity with target genes, developing algorithms for accurate prediction of miRNA targets has always been challenging. In this study, the Kronecker method and the mintRULS algorithm, the regularized least squares objective function, were used to predict the targets of plant miRNAs in the human body. Thus, by the effective features that are used in mintRULS algorithm and applying them in the plant miRNA and human mRNA sequence datasets in a similarity-based manner, we were able to achieve a very promising level of model performance as PmintRULS in the experimental dataset from 0.839 to 0.842 in identifying human target sites and classifying them into three classes of strong, medium, and weak, which indicates its high generalizability For the purpose of prognosis and treatment of various diseases.

Abstract Water deficit is one of the most important environmental stresses affecting the establishment and early growth of medicinal plants, and identifying genotypes adapted to such conditions is a crucial step toward the development of sustainable cultivation systems. In this study, the responses of four Glycyrrhiza glabra genotypes to drought stress were evaluated under two controlled environments, including laboratory and greenhouse conditions. In the laboratory experiment, drought stress was induced using polyethylene glycol (PEG 3000) at different osmotic potentials, while in the greenhouse experiment different soil moisture regimes based on percentages of field capacity were applied using a randomized complete block design with four replications. To characterize the response patterns of the genotypes, several traits were measured, including germination percentage, radicle length, plumule length, seed vigor index, chlorophyll content, proline concentration, and soluble sugar content. The results indicated that increasing drought stress significantly reduced germination parameters and seedling growth traits, and chlorophyll content also declined under stress conditions. In contrast, the accumulation of proline and soluble sugars increased under drought stress, suggesting the activation of osmotic adjustment mechanisms and protective responses in the plant. Significant differences were also observed among the genotypes in their responses to drought stress, indicating the presence of variability in their adaptive capacity. Overall, the combined evaluation of growth and biochemical indicators at the seedling stage can serve as an effective approach for identifying drought‑tolerant G.glabra genotypes.

Abstract A large proportion of the medicines used by humans are extracted directly or indirectly from plant secondary metabolites. These complex compounds, which include groups such as alkaloids, flavonoids, terpenes, and phenolic compounds, have demonstrated significant therapeutic properties, including anticancer, antibacterial, anti-inflammatory, and potent antioxidant effects. However, the increasing pressures of environmental stressors, climate change, and overexploitation of natural resources have placed many plant speciesespecially valuable medicinal plantsat risk of extinction. Under these critical conditions, traditional and direct extraction of these compounds from nature has become an unsustainable and unreliable approach. In such a scenario, plant biotechnology knowledge-particularly tissue culture techniques-has emerged as a promising solution. Methods such as suspension culture of plant cells, callus culture, production of hairy roots using Agrobacterium rhizogenes, genetic metabolic engineering of plants, and the use of advanced bioreactor systems enable the large-scale, controlled, and sustainable production of secondary metabolites in laboratory settings. In addition, these approaches provide precise control over the quality and purity of the final product and help prevent potential contaminants that may occur during traditional extraction processes. Overall, the development and application of these biotechnological strategies not only contribute significantly to the conservation of biodiversity, but also ensure a sustainable and cost-effective supply of materials to meet pharmaceutical and industrial needs for future societies. They offer a clear pathway toward the responsible use of plant resources.

Abstract Light elicitation is an emerging and controllable approach for stimulating secondary metabolite production in in vitro plant cultures. Despite the broad importance of compounds such as phenolics, flavonoids, terpenoids, and alkaloids in the pharmaceutical, food, cosmetic, and agricultural industries, their production in cell, callus, and organ cultures is often limited because of the absence of natural stress conditions. In addition to serving as an energy source for photosynthesis, light acts as an important environmental signal that regulates plant growth, morphogenesis, gene expression, and metabolic pathways through photoreceptors such as phytochromes, cryptochromes, phototropins, and UVR8. This review examines the effects of light spectral quality, irradiance intensity, photoperiod, and ultraviolet radiation on the production of secondary metabolites in plant tissue culture systems. The transition from fluorescent lamps to light-emitting diode (LED) systems has enabled precise control of light wavelength, intensity, and spectral composition, thereby facilitating the development of specific light recipes for individual plant species and target metabolites. Blue light, mainly through activation of cryptochrome-dependent signaling networks, HY5, and MYB family transcription factors, is associated with stimulation of the phenylpropanoid pathway and the accumulation of phenolic and flavonoid compounds. Red light, mediated by phytochromes, modulates photosynthetic performance, morphogenesis, and, in certain species, terpenoid and alkaloid biosynthetic pathways. Green light and combined red–blue light treatments may also induce specific and, in some cases, synergistic responses.